Understanding Transmission Shift Pattern Type and Shift Pressure Types

[mvrk10256]

2009 GMC 2500Hd w/ 6L90E

I was hoping someone could explain the differences to me.

When I look under Transmission -> Shift General, there is a Shift Pattern Type. There are two (presumably regular and tow/haul) and under the drop down there is:

Normal
Performance
Cruise
Winter
Trailer
Load Mgt
Warmup
Pattn 1
Pattn 2
Pattn 3
Pattn 4

What exactly do these mean? I selected performance but now when I put the truck in M it doesn't display the gear and the buttons don't seem to do anything.

Additionally under shift pressures there are:

Pattern X
Pattern Y
Pattern Z

Are these just 3 "maps" you can adjust or is there something specific about them?

Any help appreciated.

-M

[hjtrbo]

Generally you leave all that alone. Sorry I can't explain what effect the different settings have.
The pressure patterns can be adjusted independently in the shift pressure tab.

[SASTBone]

i too have been searching for an answer on this. my 09 is a halfton with a 60e. i have tow/haul but its not actually listed as tow haul in the ecm. how do you know what its changing? instead i see pattern 2 and 1 listed.

[TheMechanic]

Here is what I believe them to be. All are just different shift patterns that can be totally different from one another or exactly the same. Inputs like full throttle, or something like a tow/haul switch on the shift lever/dash switch will change it to that pattern. You could for example take all of your tow/haul settings and make them "bigely" aggressive so pushing the tow haul button would be like have a competition mode similar to a Corvette.
Long story short it's just a way of complicating by giving you to many options. :}

[mvrk10256]

Thanks for the answers guys. I was comparing the CTS-V stock maps and it had different names than my truck. Sounds like i need to put those back to factory and just make individual changes.

Side note - is there a way to make it hold any of the 6 gears in manual? or just the lower 4? I have tried setting that value to A6 but it doesnt seem to let me lockout 6th.

[Alvin]

You can log "shift pattern" or something along those lines to see which of the tables it's using Normal, pattern A, etc.

This is a good gut check cause there are some vehicles that default into Pattern B for example. In that particular car's case normal is the "performance shift" mode.

[TheMechanic]

You can log "shift pattern" or something along those lines to see which of the tables it's using Normal, pattern A, etc.

This is a good gut check cause there are some vehicles that default into Pattern B for example. In that particular car's case normal is the "performance shift" mode.

Exactly this. Which is why I will normally copy over all tables and copy like for like on the X Y Z also unless I want to make specific shifting for a customer but that is extra time $ to do and test. To OP Don't let it scare you just think of each name as a shift pattern number. Like this is shift patter 1 and it is for grandma who never goes past 1/4 throttle (low TM), number two is for your wife who needs to get to a purse sale at Sax. She won't go over 1/2 throttle, You get 3 and your teenage son gets shift pattern 4 because he used the gas pedal like an on and off switch.

[edcmat-l1]

It does get a little confusing. You have to know how the pressure tables correlate with the shift scheduling and timing. The pressure tables are in XYZ and the scheduling is Normal, Special, pattern A and B. The pressure pattern mode is the look up for the pressure table based on what shift pattern you're in.

[hjtrbo]

TheMechanic, right on brother. I'm the same, I literally make everything the same. Even special to normal everywhere, adapts, turbine tables, you name it. Just makes everything so much easier.

[TA_Freak]

Exactly this. Which is why I will normally copy over all tables and copy like for like on the X Y Z also unless I want to make specific shifting for a customer but that is extra time $ to do and test. To OP Don't let it scare you just think of each name as a shift pattern number. Like this is shift patter 1 and it is for grandma who never goes past 1/4 throttle (low TM), number two is for your wife who needs to get to a purse sale at Sax. She won't go over 1/2 throttle, You get 3 and your teenage son gets shift pattern 4 because he used the gas pedal like an on and off switch.

Nice. If my 6' 4" grandma were still living, she'd ask me to copy the performance table to the others - so that she'd always be in performance mode. I asked her once, "grandma, why do you always hammer the throttle coming out of your complex?" Her answer was, "I can't seen them coming so .... they won't be able to catch me anyway." LOL.